Fluid seal



UZ- 14, 1945- R. D. sNYDER Re. 22,666

FLUID SEAL Qrgnal Filed July 26, 1943 Z5 ZZ Reissued Aug. 14, 1945 FLUID SEAL Russel D. Snyder, Chicago, Ill., assignor to Crane Packing Company, Chicago, Ill., a corporation of Illinois Original No. 2,360,372, dated October 17, 1944,

Serial No. 496,096, July for reissue January 22,

10 Claims.

This invention relates in general to a fluid seal and is more particularly described as a fluid seal for shafts although it may have a more general use wherever applicable.

An important object of the invention is to provide a fluid seal of the type adapted to be preloaded upon a shaft at one end and to abut a frictional contact disk at the other .end with a driving connection between the fixed end of the sealing member and the outer periphery of the contact disk which permits a relative longitudinal movement of the driving and driven portions of the shaft.

A further object of the invention is to provide a shaft seal which may be compactly arranged to i'lt in a short space surrounding the shaft, or it may be extended to t in a longer space in a recess of smaller diameter.

A still further object of the invention is to provide a shaft sealing unit which may -be easilyassembled and taken apart and in which the sealing member is protected against spreading' out under pressure of a holding spring and thus destroying its sealing contact with the frictional contact disk.

A still further object of the invention is to provide a seal of this class in which suiiicient space is provided for applying a coil spring having more than a minimum number of turns' so that a smooth and distributed spring action is provided for maintaining the sealing member in proper sealing position.

Other and further objects of the invention will appear in thejspecification and will'b'dlapparent from the accompanying drawing in which, y

Fig. 1 is asectlonal view illustrating a sealing unit as applied to a pump shaft;

Fig. 2 is a transverse section taken on the line 2--2 of Fig. l;

Fig. 3 is a transverse section taken on the line 3--3 of Fig. 1;

Fig. 4 illustrates an extended shaft seal as applied to a shaft;

Fig. 5 illustrates a more compact shaft seal as applied to a shaft; and

Fig. 6 illustrates a modification of the sealing unit.

In the fluid sealing units as applied to pump shafts, it is desirable to provide a sealing member of flexible and resilient material such as rubber or a rubber substitute in which one end is slightly less in diameter than the shaft to which it is applied so that it must be forced or preloaded upon the shaft and thus tends to stay in position 26, 1943. Application 1945, Serial No. 573,961

Wherever placed. The other end of the sealing member is free from contact with the shaft, it has a portion extending substantially at right angles to the outer surface of the shaft and abutting a frictional contact disk, the two extremities being connected by a iiexible fold of the bellows type adapted to permit relative movement of the two ends lengthwise of the shaft 'but still maintaining the seals at the ends of the members;

Referring now more particularly to the drawing, a sealing unit is shown as applied to a shaft 8 having a surrounding casing 9 with a seal containing recess III surrounding the shaft and enclosed by an outer plate II which engages a washer I2 for making a fluidtight outer joint.

At the inner side of the plate is a contact face I3 having a smooth surface engaged by a, iric tional contact disk I4. This disk is usually composed of impregnated fabric or condensate material which has a low coefficient of friction adapted to make a lapped duid-tight driving connection with the face I3.

A flexible and resilient sealing member has a sleeve portion I5 at one end adapted to fit tightly in preloaded condition upon the shaft, and extending therefrom is a flexible bellows fold IB forming an integral connection with the other extremity I1 which has an outer face directly contacting with the exposed face of the frictional disk I4 and adapted to make a fluid-tight connection therewith.

In order to hold the resilient member more tightly upon a shaft, a sealing ring I8, either split or solid, may be applied tothe preloaded section and retained in place thereon by outer ribs or projections I! and 20, the ring being sprung or slipped over the outer rib I9 before the sealing member is applied to the shaft.

Extending outwardly from the sealing ring, preferably at opposite sides thereof, are driving projections 2| which may be formed or cut and bent depending upon the materialof which the ring is made and extending outwardly as shown more clearly' in Fig. 3.

Surrounding the outer periphery of the disk I4 and the extremity I1 of the sealing member is a sleeve 22 having depressions 23 at opposite sides adapted to form driving ribs to .engage in corresponding slots 24 extending across the outer edges of the disk as shown more-clearly'in Fig. 2.

In the sleeve isla reduced shoulder 25 engaged by a thin ring 26 of metal or other suitable material which abuts the outer face of the flanged extremity I'I of the resilient sealing member to at one end. a. flange at conm it against tact disk Il and At the inner edge oi' the reduced portion of the sleeve are slots 21 to engage the projections 2| of the ring I8 andto permitY relative movement oi' the ring and sleeve along the shaft. v

As the preloaded portion of the sealing unit will adhere tightly to the shaft, it is nece only to interpose a coil spring 30 between the edge of the sleeve 22 and some suitable abutment such as a ilanged ring 3| in engagement with a shaft shoulder 29.

If a close coupled arrangement is desired, the sleeve 22 is formed with a flange 32 at its outer end as shown at Fig. 5, a hanged ring 33 is applied to the shaft. and the coil spring 3l is interposed between the flanges 32 and 33. A groove Il and a snap ring 35 therein may be substituted for a shoulder 29 in supporting the ring 33 onthe shaft. Y

With both forms of construction, it is therefore possible to use a coil spring having more than a minimum number oi' turns so that it will have 'a smooth and distributed spring action which is more likely toapply and hold the sealing member in proper sealing condition.

If it is desirable to provide a sealing unit in which the sealing member is protected against external pressure or suction from along the shaft, member 4I as shown in-Fig. 6 l

a frictional contact maybe provided, having a projecting shoulder 42 extending inwardly within is otherwise protected, as shown and described.

In these forms of the invention, it will be seen um the ribs' z: form s driving connection be- 'l is placed at the inner side of the flanged extremity I1, the sleeve 22 is applied over the outside, and the frictional disk Il is inserted within the sleeve at the end thereof. 'I'he conning ring I8 is assembled upon the sealing member sleeve portion II and the projections 2l are seated in the slots 21 o! the driving sleeve 22.

A positive driving connection is thus provided in the sealing unit, from `a shaft towhich it. is applied through the preloaded sleeve portion I5, tight ntting drive ring Il, Projections 2| in slots 21 of sleeve 22, sleeve driving ribs engaging in slots 24. At the same` time a iexi'ng movement lengthwise of the shaft is permitted by the ilexible bellows fold Il, the parts being held resiliently in position by the spring 2U which tends to extend the bellows fold.

I claim:

1. A shaft'seal unit having a ilexible and resilient sealing member with a preloading sleeve the other end and a resilient expansible connection between them; a frictional contact disk engaging the nange havdriving notches in its edge, a sleeve withribs to engage the notches and a reducing shoulder to engage the side of the 1in-nge, and driving means comprising a confining ring surrounding the preand supporting the inner periphery 43 of the sealing member which connected and assembled contact disk. I easily removed from its engage- '.1'-

assembled and' their connections with each the parts, the contactu'ing 28' loading sleeve and an extensible connection between the sleeve and the ring.

2. A. shaft sealing unit on the free end of the sleeve, a compressed coiled spring encircling the shaft and rotating there- 1| with, a second sleeve surrounding the rubber-like sacco sleeve and the disc ribs formed in the inner face of the second sleeve and contained within slots in the periphery of the disk to constitute a driving connection between the sleeve and the disk, and a shoulder abutment carried on the shaft and against which one end of the coiled spring abuts, the other end of the coiled spring abutting the end of the second sleeve, 'whereby the compression in the spring urgesthe second sleeve and disk towards the inner i'ace of the stationary member. I

'1. In a iluid seal of lthe lcharacter described, the combination with a rotatable shaft projecting through an orifice in a stationary member and a rubber-like sleeve formed with a yielding fold intermediately of its length and surrounding and rotating with the shaft and tightly gripping the shaft at one end of the sleeve and being free of the shaft at the of a disk mounted on the shaft and interposed between the free end of the sleeve and the inner face of the stationary member and adapted to of the coiled spring other end of the sleeve.

rotate with the shaft and sleeve, a compressed coiled spring encircling the shaft and rotating therewith, a second sleeve surrounding the rubber-like sleeve and the disk, a clamping member surrounding the portion of the rubber-like sleeve which tightly grips the shaft, driving lugs projecting from the clamping member to enter slots in the second sleeve, and a shoulder abutment carried on the shaft and against which one end of the coiled sp t abuts, the other end of the coiled spring abutting the end of the second sleeve, whereby the compression in the spring urges the second sleeve,'free end of the rubberlike member and the disk towards the inner face of the stationary member.

`8. In a iiuid seal of the character described, the combination with a rotatable shaft projecting through an orifice fold intermediately of its length and surrounding and rotating with the shaft and tightly gripping the shaft at one end of the sleeve and being in the stationary member4 and a. rubber-like sleevetformed with a yieldingl between the free end of free of the shaft at the other end of the sleeve. of a disk mounted on the shaft Iangl the sleeve and the inner face of the stationary member and adapted to rotate with the shaft and sleeve, a iiangeformed on the free end of the sleeve, a compressed coiled spring encircling the shaft andvrotating therewith, a second sleeve surrounding the rubberlike sleeve and embracing Ithe periphery of the flange and the periphery of the disk to rotate therewith. a clamping member surrounding the portion of the rubber-like sleeve which tightly grips the shaft, driving lugs projecting from the clamping member to be slidably contained in slots in the second sleeve, and a shoulder abutment carried on the shaft and against which one end of the coiled spring abuts, the other end abutting the end of the second sleeve, whereby the compression in the spring urges the ange on the free end of the rubberlike sleeve towards the disk and the disk into iluidtight contact with the inner face of the stationary member.

9. In a sealing unit for effecting a fluid I seal between two relatively rotatable elements, a sealing washer encircling one of the elements, and resilient and compressible means for eitecting a fluid-tight seal between the washer and the element it encircles, saidmeans having a fold for permitting the washer to move relatively to the said element, a portion of the fold adjacent the washer extending radially inward in close proximity to the said element such that the pressure of the iiuid to be sealed will tend to torce -the fold into contact with the said element, and means interposed between the inwardly extending portion oi the fold and said element for preventing said portion of the fold from contacting the said element, said last-mentioned means being freely movable on the said element.

l0. A sealing unit as described in claim 9, said V last-mentioned means comprising an extension on lthe washer.

RUSSEL D. SNYDER. 

